.\" RCSid "$Id: genblinds.1,v 1.6 2009/04/24 05:20:22 greg Exp $"
.TH GENBLINDS 1 10/10/94 RADIANCE
.SH NAME
genblinds - generate a RADIANCE description of venetian blinds
.SH SYNOPSIS
.B "genblinds mat name depth width height nslats angle"
[
.B "\-r|+r rcurv"
]
.SH DESCRIPTION
.I Genblinds
produces a RADIANCE scene description of a set of venetian blinds.
The
.I depth
of the blinds (X dimension) is given first, followed by the
.I width
(Y dimension), followed by the
.I height
(Z dimension).
The number of slats to place evenly within this height is given as
.I nslats.
The
.I angle
of the blind, where zero is perfectly horizontal and a
positive angle tilts the positive X edge upwards, is
given in degrees.
The blinds are initially situated so that the corner of the bottom blind is
.I "height/nslats/2"
above the XY plane, and all coordinates are positive.
Each new slat is placed
.I "height/nslats"
above the previous one, until the top slat is at
.I "height - height/nslats/2".
The blinds may of course be moved from this starting point with the
.I "xform(1)"
command.
.PP
If curved blinds are desired, a radius of curvature may be given
with the
.I "+/-r"
option.
If given as
.I +r,
The curvature is upward (which is the usual configuration).
If the option is given as
.I -r,
then the curvature is downward.
The radius indicates how far from each slat its effective
cylindrical center resides.
Each slat will be broken into as many polygons as is necessary to
keep the delta changes in angle less than 10 degrees.
(Note that this may result in a rather large number of polygons.)\0
.SH EXAMPLE
To produce a curved set of blinds with 25 slats at 15 degrees:
.IP "" .2i
genblinds white blind 1 46 88 25 15 \-r 1 > blinds.rad
.SH AUTHOR
Jean-Louis Scartezzini and Greg Ward
.SH "SEE ALSO"
genbox(1), genrev(1), gensurf(1), genworm(1), rpict(1), rvu(1), xform(1)
